Intercept download and change file name

Question

I maintain a Google Chrome extension that fixes multiple annoyances with a specific web-based product. One such annoyance is that downloaded files' names are useless so I want to be able to intercept the download and change the file name to a useful one.

As per https://julienharbulot.com/chrome-extension-gutenberg.html and multiple StackOverflow posts, I have:

Updated manifest.json to include "permissions": [ "", "downloads"] and "background": { "scripts": ["background.js"], "persistent": false }
Created background.js with the following content just as a proof of concept but nothing gets logged to the console so I can only assume that the product doesn't use chrome.downloads or something:
```
chrome.downloads.onDeterminingFilename.addListener(function(item, suggest) {
    console.log(item.referrer);
    console.log(item.filename);
});
```

Updated the content script to include the following but nothing relevant seems to get logged to the console when I trigger a download:

MutationObserver = window.MutationObserver || window.WebKitMutationObserver;

var observer = new MutationObserver(function(mutations) {
    mutations.forEach(function(mutation) {
        if (!mutation.addedNodes) return

        for (var i = 0; i < mutation.addedNodes.length; i++) {
            var node = mutation.addedNodes[i];

            console.log(node);          
        }
    })
});

observer.observe(document, {
    subtree: true,
    attributes: true,
    childList: true
});

Is there another way that I can detect how the product is invoking downloads and override it?

Intercept download and change file name

0 Answers